The present invention relates to methods and apparatus for tracking the sun and more particularly, to methods and apparatus by which a photovoltaic panel or any other sun energy conversion device can be positioned to capture the maximum useful radiation available from the sun as it makes its diurnal trek across the skies.
While the present invention will be presented in the context of tracking the radiation from the sun, the invention is applicable to tracking of radiation of other sources as well, as will be apparent to those versed in the art, and as will be obvious from the description which follows.
It has long been recognized that for the most efficient generation of electrical energy from solar radiation it is necessary for the converting apparatus to track the path of the sun. Numerous schemes have been devised for achieving this goal, but prior to the present invention, none has provided a truly practical solution.
Tracker controls using freon as the active medium are known in the art, but are characterized by unreliability in even ideal atmospheric conditions and outright inoperability when either the temperature or the wind conditions are adverse, and are virtually useless for concentrator collectors where accuracies of less than five degree are demanded.
Highly sophisticated, computer-driven trackers which employ a database to calculate the position of the sun at any given instant of time for a particular location on the planet have also been devised, but are only experimental and have not found any commercial success whatsoever due to their extremely high cost and periodic need for calibration.
The present invention, for the very first time, provides methods and apparatus for tracking the sun which are simple in design and inexpensive to produce, while at the same time precise to within a fraction of a degree under any temperature conditions or windy weather, as well as more ideal conditions. In addition, the present invention provides a tracking device which is self-powered, instantly recognizes atmospheric conditions which affect the collection of solar radiation and modifies its operation to best suit those conditions, prevents elevation "skying" in diffuse radiation conditions and automatically returns to the east after sunset.
An additional object of the invention is to provide a low cost, high precision tracker control that tolerates imbalances in sensor pairs due to manufacturing tolerances, environmental conditions and aging.
Accordingly, it is an object of the present invention to provide a low-cost, highly accurate control system for a solar tracker which maximizes the gathering of solar energy.
It is a further object of the present invention to provide a method for controlling the position of a solar collector to maximize the amount of solar radiation that it collects.
Yet another object of the present invention is to provide a control system for a solar tracker that automatically recognizes a variety of atmospheric conditions affecting the collection of solar radiation and modifies the tracker's operations to best suit those prevailing conditions.
Another object of the invention is to provide a method and apparatus by which a solar tracker will automatically return to an east position after the sun sets.
Yet a further object of the present invention is to provide methods and apparatus for solar tracking that will prevent the elevation control from "skying" in diffuse light conditions.
Other objects and advantages will appear from the following description of a preferred embodiment of the invention and the novel features will be particularly pointed out in the claims.